A comparison of the tensile deformation behaviors of austenitic and martensitic stainless steels was made. The austenitic stainless steel used in this study was SUS 304 water-quenched from 1050℃, and the martensitic stainless steel SUS 410 air-cooled from 1000℃ and subsequently tempered at 750℃ for an hour. The detailed comparison for deformation characteristics of two stainless steels was summarized in Table 2.